Lifecycle

Introduction

If we are talking about services we also have to talk about priority startup and shutdown. You want your services being started and stopped in an orderly manner.

You can use Ninja's @Start and @Dispose annotations to do so.

Example

The class and method then looks like:

@Singleton
public class MyService {

    @Start(order = 90)
    public void startService() {
        //do something       
    }

    @Dispose(order = 90)
    public void stopService() {
       //do something
    }

    public Result getCount(Context ctx) {
        return Results.json(count.get());
    }
}    

Don't forget to bind the class explicitly inside conf/Module.java

public class Module extends AbstractModule {

    protected void configure() {

        bind(MyService.class);

    }
}

By that Ninja will start MyService and also stop it nicely.

Starting and stopping services in order

The order in which it should be started, higher meaning later. While apps are free to use any ordering system they wish, the following convention is recommended:

• 10 - Services that connect to resources and do not depend on other services, for example, database connections
• 20-80 - Services that depend on resources, but don't actually start the app doing its core functions
• 90 - Services that start the app doing its core functions, for example, listen on queues, listen for HTTP, start scheduled services